Secured force concentrator in a vehicular bolster for airbag retention and deployment

ABSTRACT

A vehicle seat assembly includes a frame for mounting the seat to a vehicle. The seat assembly also includes a seat pad located proximate the frame. A trim cover is disposed over the seat pad, and includes a seam adjacent a side of the seat pad. An airbag assembly, which includes an airbag and an inflator configured to supply gas to the airbag, is also part of the seat assembly. A force concentrator covers at least a portion of the seat pad for protecting the pad during deployment of the airbag. The force concentrator includes an inner panel attached to the airbag assembly and an outer panel attached to the frame. The panels form a deployment channel for the airbag, and thereby inhibit contact of the airbag with the seat pad as the airbag deploys.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority benefits under 35 U.S.C.§119(a)-(d) to DE 10 2006 053 601.0, filed Nov. 14, 2006, which ishereby incorporated by reference in its entirety. This application alsoclaims priority to and is a continuation of U.S. Ser. No. 11/779,594filed Jul. 18, 2007.

DESCRIPTIONS

1. Field of the Invention

The invention relates to a vehicle seat assembly, and in particular, aseat assembly with a secured force concentrator in a bolster thereof forretaining and deploying a side airbag.

2. Background Art

Vehicles today are often equipped with side airbags. They may take theform of an airbag disposed within the seat back or cushion of a vehicleseat assembly. One limitation of airbags that are located within a seatassembly is that the airbag needs to break through the seating materialbefore it can fully deploy to protect a vehicle occupant. Duringdeployment, such an airbag may encounter foam or other seat padmaterials. It must then break through a seat trim cover in order toescape from the seat assembly.

A number of attempts have been made to facilitate deployment of airbagsfrom and through a vehicle seat assembly. One such device is describedin U.S. Pat. No. 5,816,610 issued to Higashiura et al. on Oct. 6, 1998.Higashiura et al. describes a seat structure having a side impact airbagapparatus. A side bolster pad of the seat structure may be made fromfoam, in which case the airbag apparatus is surrounded by a liningmember. The lining member has a perforation to facilitate its breakingwhen the airbag deploys. The side bolster itself is covered with asurface layer having a seam almost directly opposite the perforation inthe lining member. In this way, the airbag deploys through theperforation in the lining member, breaks through the foam of the seatpad, and exits the seat structure through the seam in the surface layer.One limitation of the seat structure described in Higashiura et al. isthat the airbag must deploy through the seat pad before exiting the seatstructure. In particular, the airbag, which may be moving with very highvelocity, impacts the foam seat pad as it exits the seat structure. Thiscan cause pieces of the seat pad to be expelled from the seat as theairbag exits the seat cover. Therefore, a need exists for a seatassembly that includes protection for the seat pad from the deployingairbag.

Another device is described in U.S. Pat. No. 6,045,151 which issued toWu on Apr. 4, 2000. Wu describes a seat assembly including a side airbagwith a force concentrator that surrounds the airbag to concentrate anddirect the force of the inflating airbag by a pre-determined deploymentseam so that the seam may rupture and allow the airbag to deploytherethrough. Wu discloses two embodiments of the force concentrator:(1) a layer of sheet material joined to the inside of the trim cover;and (2) a sleeve or pocket of sheet material which entirely surroundsthe airbag module. '151 Patent, col. 2, lines 51-65.

Other patents of interest include U.S. Pat. No. 5,816,610 which issuedto Higashiura et al. on Oct. 6, 1998; U.S. Pat. No. 5,860,673 whichissued to Hasegawa et al. on Jan. 19, 1999; U.S. Pat. No. 5,927,749which issued to Homier et al. on Jul. 27, 1999; and U.S. Pat. No.6,206,410 which issued to Brown on Mar. 27, 2001.

SUMMARY OF THE INVENTION

The prior art leaves at least partially unsolved the problem ofdesigning and assembling vehicle seats with a side airbag that can bedeployed consistently, regardless of the physical properties of the seattrim cover and seat foam pad.

It would be useful to have a seat with a side airbag, the deployment ofwhich does not vary significantly over time, regardless of the extent ofwear and imperfection or damage sustained by the trim cover.

The present invention provides a vehicle seat assembly including a seatpad and a force concentrator configured to facilitate the manufacturingprocess and protect the seat pad during deployment of an airbag fromwithin the side bolster.

The invention further provides a vehicle seat assembly including a framefor mounting the seat to the vehicle. A seat pad is disposed proximatethe frame. A trim cover is disposed at least partially over the seatpad, and includes a seam adjacent a side of the seat pad. An airbagassembly is provided, which includes an airbag and an inflator which isconfigured to supply gas to the airbag, thereby facilitating itsdeployment. A force concentrator covers at least a portion of the seatpad for protecting the seat pad during deployment of the airbag. Theforce concentrator includes multiple panels—preferably, inner and outerpanels—that form a deployment channel therebetween for the airbag,thereby avoiding contact of the airbag with the seat pad duringdeployment during expansion.

For added rigidity, in one embodiment, the inner panel has one endsecured to a frame member. The outer panel, in some embodiments,fastens, for example, by a hook to the airbag module itself.

The panels of the force concentrator cooperate with each other such thatdeployment of the airbag along the deployment channel moves a portion ofthe seat pad away from the deploying airbag, while avoiding contactbetween the seat pad and the deploying airbag. The orientation of thedeployment channel facilitates deployment of the airbag through the seamin the trim cover so that substantially all of the deployment forces aredirected to the deployment channel, thereby increasing the speed atwhich the airbag deploys.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a quartering perspective view of a portion of the backrest ofa seat assembly in accordance with the present invention;

FIG. 2 is a sectional view of inner and outer panels of a forceconcentrator located in the seat assembly shown in FIG. 1, taken throughthe line A-A;

FIG. 3 is a quartering perspective view of the panels in isolation fromthe view of FIG. 1 with the airbag and most of the housing removed, inwhich the panels are attached to a structural member of the seatback andto part of the housing; and

FIG. 4 resembles the view of FIG. 2, but illustrates an embodiment inwhich the inner panel is affixed to the side airbag module and the outerpanel is secured to the vehicle frame.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

The invention relates to the integration of a multi-part, preferably atwo-part panel—the inner and the outer panel—in a rear backrest orcushion of a seat that is mounted in a vehicle. As used herein, theterms “inner” and “outer” respectively are used in relation to proximityto the vehicle seat occupant and the vehicle door.

FIG. 1 shows a portion—for example, a rear side bolster—of a seatassembly 10 in accordance with the present invention. It should berealized that although a rear side bolster is illustrated, the inventionis not so limited. The invention can reside in any seatback or seatcushion. The seat assembly 10 includes a side bolster 12 and seat pad 16that is at least partially covered by a trim cover 18. The seat pad 16preferably is made from a molded polymeric material, such as apolyurethane foam. The use of a polymeric foam material to construct theseat pad 16 is cost effective and provides the flexibility needed tochange the shape of the seat pad for different types of seat assemblies.Of course, other types of polymeric materials may be molded to form theseat pad 16.

Disposed within the side bolster 12 is an airbag assembly or module 20.As shown in FIG. 2, the airbag assembly 20 includes an airbag and aninflator 24, which is configured to supply gas to the airbag 22, therebyfacilitating deployment of the airbag 22. Also shown in FIG. 2 is aportion of a seat frame 26 which can be used for mounting the airbagassembly 20 to the seat assembly 10. The seat pad 16 is disposedproximate the frame 26 and may be directly attached to the frame 26 atvarious locations.

The trim cover 18 includes a seam 28 which is adjacent to a side 30 oranother side of the seat pad 16. It should be appreciated that the seam28 is a tear seam that could be located on the trim in front of themodule or at other locations that are generally in the direction ofdeployment of the airbag from the module. Covering at least a portion ofthe seat pad 16 is a force concentrator 32 which protects the seat pad16 during deployment of the airbag 22. Inner (first) 34 and outer(second) 36 panels also have the function of directing the force of thedeploying airbag directly into the tear seam. The forces of deploymentare initially directed against members by which the housing is securedin relation to the frame of the seat. The deployment forces then areexerted against the panels 34, 36, thereby focusing deployment forcesupon the seam 28 without significant diversion.

Comprising inner 34 and outer 36 panels, the force concentrator 32 maybe made from any material effective to protect the seat pad 16 duringdeployment of the airbag 22. For example, a woven or non-woven clothmaterial, which may include natural or synthetic materials such asnylon. One material that is found to be effective is a polyamidematerial, of the type from which the airbag 22 may be manufactured.Regardless of the type of material used to make the force concentrator32, the use of the force concentrator 32 can reduce friction on theairbag 22 as it deploys. Although a polymer such as nylon may beparticularly beneficial, even a fleece material will help reduce thefriction on the airbag 22. This is because the force concentrator 32inhibits contact between the deploying airbag 22 and the seat pad 16.

In the embodiment shown in FIG. 2, the force concentrator 32 effectivelyprohibits all contact between the deploying airbag 22 and the seat pad16. This helps to prevent energy loss from the airbag 22 by decreasingfriction and protecting the seat pad 16 from damage. This, in turn,helps to reduce the deployment time of the airbag 22.

As shown in FIG. 2, the force concentrator 32 includes inner and outerpanels 34, 36 which form a deployment channel 38 for the airbag 22. Asthe airbag 22 deploys from the housing 40 through the deployment channel38, the force concentrator 32 inhibits contact between the airbag 22 andthe seat pad 16. Thus, portions of the seat pad 16 are moved away fromthe airbag 22 as it deploys through the deployment channel 38.

The deployment channel 38 is oriented to facilitate deployment of theairbag 22 through the seam 28 in the trim cover 18.

In particular, the airbag assembly 20 includes a housing 40 which atleast partially surrounds the airbag 22 and the inflator 24. The housing40 can resemble a clamshell cover with its split line 39 oriented towardthe tear seam 28. The housing 40 includes a frangible portion which isbroken by the airbag as it deploys. The frangible portion 60 is disposedopposite the deployment channel 38 to facilitate deployment of theairbag along the channel 38 and out from the seam 28.

Although the airbag housing 40 comprises a relatively rigid material, inother embodiments, a thin sheet of material may be used in place of arigid housing. In such embodiments, the sheet may contain a frangibleportion, as its properties will be such that it will tear as the airbag22 deploys.

As shown in FIGS. 2-3, the inner and outer panels 34, 36 of the forceconcentrator 32 respectively include ends 62, 64 that are attached tothe trim cover 18 at the seam 28. This configuration helps to facilitatedeployment of the airbag 22 through the seam 28. The deployment channel38 opens as the airbag 22 is deployed, thereby causing the panels 34, 36to exert an outward force on the trim cover 18 at the seam 28. Thisruptures the seam 28 and provides an exit path for the airbag 22.

The airbag seam 28 preferably is sewn through the edges of ends 62 and64 with both sides of the trim between them. It will thus be appreciatedthat in most embodiments, the seam 28 extends between all four layers.

As mentioned earlier, the force concentrator 32 includes two separatepanels 34, 36. In FIG. 3 the end 62 of the inner panel 34 of the forceconcentrator 32 is attached at the seam 28 (FIG. 2) of the trim cover18. A distal end 63 of the inner panel 34 of the force concentrator 32is attached to the seat frame 26. This provides a convenient means forsecurely attaching the inner panel 34 of the force concentrator 32.

Similarly, the seam end 64 of the outer panel 36 of the forceconcentrator 32 is attached at the seam 28 of the trim cover 18. Adistal end 65 of the outer panel 36 of the force concentrator 32 may beattached to the side airbag module 20.

Thus, the force concentrator 32 not only provides a deployment channelfor the airbag 22, but also protects the seat pad 16 from damage duringhigh velocity deployment.

In FIG. 3, reference numerals 66, 67, respectively, designate retainers,for example, one or more J-clamps, that respectively affix the distalends 63, 65 of the inner and outer panels to the seat frame 26 and tothe side airbag module 20. It will be appreciated that the retainers 66,67 have a shape that is not limited to those depicted in FIG. 3.

It will also be appreciated that, as depicted in FIG. 4, if desired,depending upon the application, the inner panel 34 may be affixed to theside airbag module 20. Alternatively also, the outer panel 36 may have adistal end 65 that is secured to a portion of the seat frame 26.

One methodology by which the pad, trim, and airbag module may be affixedto a side bolster is as follows:

A. Placing the bolster, which includes the wire frame that preferably ismolded in situ, with the deployment channel opening upwardly;

B. Placing the trim on top of the bolster, while aligning the airbagseam with the opening of the deployment channel;

C. Feeding the panels, which are sewn to the trim, into and through thedeployment channel;

D. Affixing the trim to the bolster (e.g., by retainers or otherfasteners);

E. Mounting the inner panel to the wire frame as shown in FIGS. 2-3; FFastening the outer panel to the side airbag module or as shown in FIGS.2-3;

G. Placing the airbag module between the inner and outer panels, andinto the cavity of the bolster; and

H. Feeding the threaded bolts through the holes of the airbag housing.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. A vehicle seat assembly, comprising: a frame for mounting the seatassembly to a vehicle; a seat pad disposed proximate to the frame with aportion or portions spaced apart from the frame; a trim cover disposedover at least a part of the seat pad and including a seam adjacent aside of the seat pad; an airbag assembly securely attached to the frameso that rigid reaction surfaces are provided against which forces ofdeployment may be exerted, the airbag assembly including an airbag andan inflator configured to supply gas to the airbag, the airbag assemblyhaving a clamshell housing at least partially surrounding the airbag,the clamshell housing including a frangible split line proximate to theseam to facilitate deployment of the airbag along an uninterrupteddeployment channel so that upon airbag deployment, the frangible splitline breaks and the clamshell housing opens and applies a rupturingforce at each side of and across the seam; a force concentrator coveringat least a portion of the seat pad for protecting the seat pad duringthe deployment of the airbag, the force concentrator including inner andouter panels and forming the deployment channel therebetween for theairbag; the inner panel extending substantially along an entire side ofthe clamshell housing, the inner panel including a distal end secured tothe airbag assembly, the inner panel interfacing with the seat pad alongsubstantially all of the inner panel; and the outer panel extendingalong a part of another side of the clamshell housing to facilitateassembly, the outer panel having a distal end secured to a portion ofthe frame, the outer panel interfacing with the seat pad alongsubstantially all of the outer panel.
 2. The vehicle seat assembly ofclaim 1, wherein the deployment channel is oriented to facilitatedeployment of the airbag through the seam in the trim cover.
 3. Thevehicle seat assembly of claim 1, wherein the inner and outer panels ofthe force concentrator each include a proximal end attached to the trimcover at the seam.
 4. The vehicle seat assembly of claim 1, wherein theclamshell housing at least partially surrounds the airbag, and thefrangible split line is offset from the seam.
 5. The vehicle seatassembly of claim 4, wherein the panels cooperate to form the deploymentchannel proximate a front of the airbag housing.
 6. The vehicle seatassembly of claim 5, wherein the inner panels and the trim are sewntogether by the airbag seam.
 7. A vehicle seat assembly, comprising: aframe for mounting the seat assembly to a vehicle; a seat pad disposedproximate the frame; a trim cover disposed over at least a part of theseat pad and including a seam adjacent to a side of the seat pad; anairbag assembly, including an airbag and an inflator configured tosupply gas to the airbag, thereby facilitating deployment of the airbag;and a force concentrator covering at least a portion of the seat pad forprotecting the seat pad during deployment of the airbag, the forceconcentrator including an inner panel extending between the seam and theairbag assembly and an outer panel extending between the seam and theframe, the panels cooperating with each other to form a deploymentchannel therebetween for the airbag such that deployment of the airbagalong the deployment channel moves a portion of the seat pad away fromthe deploying airbag, while the force concentrator inhibits contactbetween the seat pad and the deploying airbag, the orientation of thedeployment channel facilitating deployment of the airbag through theseam in the trim cover, so that deployment forces are substantiallydirected toward the seam by the panels.
 8. The vehicle seat assembly ofclaim 7, wherein the airbag assembly includes a housing at leastpartially surrounding the airbag, the housing including a frangibleportion to facilitate deployment of the airbag along the deploymentchannel.
 9. The vehicle seat assembly of claim 8, wherein the inner andouter panels of the force concentrator cooperate to form the deploymentchannel proximate a front of the airbag housing.
 10. The vehicle seatassembly of claim 9, wherein the inner panel of the force concentratorincludes a proximal seam end attached to the trim cover at the seam, anda distal end attached to the airbag assembly.
 11. The airbag assembly ofclaim 9, wherein the outer panel has a distal end secured to the frame.12. A method of producing the vehicle seat assembly of claim 1,comprising the steps of: A. locating a bolster, which includes a wireframe with a deployment channel opening upwardly; B. placing a trimmaterial on the bolster, while aligning an airbag seam with the openingof the deployment channel; C. feeding a force concentrator having innerand outer panels, which are sewn to the trim, into and through thedeployment channel; D. affixing the trim to the bolster; E. mounting theouter panel to the wire frame; F. placing an airbag module adjacent theouter panel, and into the cavity of the bolster; G. fastening the innerpanel to the airbag module; and H. securing the airbag housing to thewire frame, thereby providing a rigid reaction surface against which theforces of deployment may be exerted.
 13. A method of producing thevehicle seat assembly of claim 1, comprising the steps of: A. installingthe seat pad, which includes the frame and the deployment channel; B.placing the trim cover on the seat pad, while aligning the airbag seamwith the deployment channel; C. feeding the force concentrator with itsinner and outer panels, which are sewn to the seam, into and through thedeployment channel; D. affixing the cover to the seat pad; E. affixingthe inner panel to the airbag assembly; F. placing the airbag assemblybetween the inner and outer panels and into the seat pad, the airbagassembly having the clamshell housing and the split line adjacent theseam that opens against the inner and outer panels of the forceconcentrator, so that the inner and outer panels interface with thesides of the clamshell housing and directing deployment along adeployment channel; G. fastening the outer panel to a portion of theframe; and H. securing the airbag housing to the frame, therebyproviding a rigid reaction surface against which the forces ofdeployment may be exerted to rupture the seam.